Uniform-tension loom feeder



May 24, 1938. E. G. JEGGE ET AL.

UNIFORM TENSION LOOM FEEDER Filed June 17, 1932 4 Sheets-Sheet 1 eff/warm 3% 341% M y 24, 1938. E. e. JEGGE ET AL UNIFORM TENSION LOOM FEEDER Filed June 17, 1932 4 Sheets-Sheet 2 QQN ff/oral Biff,

y 1938. E. G. JEGGE ET AL I 2,1 8,046

UNIFORM TENSION LOOM FEEDER Filed June 1'7, 1952 4 Sheets-Sheet 3 Q N E Q %W ECDWI IIUHIIIII-IHHHIWHEE Tl;

$1M didmm W mwy 1938- E. G. JEGGE ET AL I 2,118,046

UNIFORM TENSION LOOM FEEDER Filed June 1'7, 1932 4 Sheets-Sheet 4 Patented May 24, 1938 PATENT OFFICE 2,118,046 UNIFORM-TENSION LOOM FEEDER Emil G. Jegge, Montclair, and schmar, Garfield,

George W. Kretz- N. J.

Application June 17, 1932, Serial No. 617,900

24 Claims.

This invention relates to a Warp feeder or letoff mechanism for looms and more particularly to a warp feeder mechanism which may be em ployed in connection with any form of loom and which is automatically adjustable to provide uniform tension of a predetermined amount throughout the warp, irrespective of fluctuations or irregularities in the operation of the loom.

It is an object of this invention to provide a let-off mechanism which will maintain a uniform and even tension on the warp threads during the operation of a loom for any given wind-up or draw-off from the warp beam.

Another object of the invention is to provide a warp feeder mechanism which is adapted to respond to very slight variations which would otherwise change the tension on the warp threads and which will relieve tension on the warp when the shed opens, thereby maintaining constant tension. The warp-feeder mechanism should be so sensitive that it reacts to the slightest variation in the length of the threads due to the wind-up, action of the harness and reed, or stretching of the threads by immediately changing the rate of let-off without varying the tension on the threads.

Another object of the invention is to provide a let-off or Warp feeder mechanism which is sufiiciently delicate in making adjustments automatically so as to provide uniform tension, so that with proper reed adjustment there will be no starting marks or barre in even the most delicate fabrics. By maintaining such a constanttension at all times on the warp threads the goods will thereby be prevented from slipping over thewind-up roll and will provide the exact required number of picks per inch at all times.

Another object of the invention is to provide a warp feeder mechanism which is constructed in such a manner that While the warp threads are passing through the loom onto the wind-up roll, the operation of the loom may be stopped for a very considerable period of time, at least for several hours, without making starting marks in the fabric produced on the loom when the mechanism is again put into operation. In other words, the let-off mechanism of this invention is so sensitive in operation that it will counteract any stretching of the threadswhilc the loom is standing, thus doing away with any starting marks.

Another object of the invention is to provide a warp feeder mechanism which is adapted to be readily set for any desired tension on the warp threads at the beginning of a run and main-- tain this tension constant during the run, so that during the operation of the loom there is no necessity for manual adjustment of weights or springs to maintain uniformoperation.

A further object is to provide a whip roll mounting and support that is quick-acting and free-floating under tension to accurately control the let-off.

These and other objects which will be apparent from the subsequent description are all embraced within the scope of this invention as set forth in the appended claims.

Various attempts have been made in the prior art to provide means for maintaining a constant tension on the warp threads during a Weaving operation and to compensate for the varying diameter of a Warp beam duringa run, it having been realized that it is impossible to employ a constant rate of rotation of the warp beam during the let-off, in which the diameter of the warp beam necessarily decreases. None of these prior art devices have been wholly satisfactory commercially.

As operating the warp beam at a constant rate of rotation during the run was found not to be feasible, proposals were made to employ friction devices including ropes, brakes, springs, etc., on a free running warp beam but none of these proposed devices would give a constant tension on the threads for the entire operation. If the brake were set for a given tension with the beam full, this tension would increase as the diameter decreased due to the diminishing radius of the threads while the effective radius of the brake remained constant.

Various devices have also been proposed employing positive let-offs with compensating mechanism responsive to the varying diameter of the warp beam. Some of these prior art devices are controlled by the varying diameter of the warp beam while others depend upon rollers, whip rolls and other tension controls. In all of these devices, however, it has not been possible to secure an absolutely uniform tension throughout the weaving operation as the diameter of the warp beam decreases.

In the present invention, a positive let-off has been provided which is so sensitively controlled that a constant tension on the warp threads is maintained regardless of the diameter of the warp beam or the'position of the whip roll which varies with the length of the warp threads between the lease rods and the warp beam.

The present device is extremely sensitive and quick acting. Since a textile thread is very elastic and will stretch at the slightest pull (of wind-up reed or harness action) any device used porting a weight to feed or hold back this thread must act instantaneously or else the threads will suffer and this in turn will show in thread breakage or in the weave. r

In the present invention, by the arrangement of parts, the ratio of the levers, the position of the whip roll to the lever fulcrum, the use of ball bearings and machined surfaces, a mechanism has been created which is'so sensitive that the I the length of the threads action of the harness and slightest variation in due to the wind-up, reed, diately on the whip roll which in turn moves a weight without increasing or altering the ten sion and changes the rate of rotation of the warp beam to restore the whip'roll to its normal position without at any time changing the tension on the threads.

The loom feeder or let-off of the present invention is capable of wide adjustment and operates equally well on heavy or lighttension, high or low pick jobs. When woven on a loom fed by this let-off, the cloth is free from barreand is smooth and uniform whichis not possible with rope or spring tension devices of the 'priorjart. When adjusted at the beginning of any weaving operation a uniform tension throughout the warp is maintained without any re-adjustment. Perfe'ct joinin gs may bemade, starting marks are entirely eliminated, and l5 to 20% less breakage is obtained, as compared with the use of the ordinary warp feeders resulting in a corresponding increase in production. There is no increased strain on the warp when the shed opens and the tension remains constant. The present invention is particularly designed for'use'with' a positive let-off warp beam. A whip roll support comprising pivoted arms extends toward the-loom, withantifriction bearings providedat .the .pivots. Awhip roll is mounted in anti-friction bearings on whip roll mountings to have an effective position at a mid-point of the pivoted arms. To maintain a constant tension on thethreads passing. over the w p roll regardless'of shedding Orpicking, apivoted lever supis connected by an adjustable link to a member extending between the ends of the pivoted arms. The rate of let-off is controlled by an adjustable lever fastened in a fixed position with respect to the pivoted arm of the whip roll support and moveable with respect to the same pivot. A pawl reciprocably operated by a going part of the loom engages a ratchet for rotating the warp beam. A pawl guard is operated by the lever which controls the position of the guard and the number of teeth engaged by the pawl and determines the rate of rotation of the warp beam.

1 In the accompanying drawings forming a part of this application and illustrating a preferred embodiment of the invention, like numerals are employed todesignate like parts throughout the same.

Fig. 1 is a side view in diagrammatic form showing the preferred form ,of the let-off or warpfeeder mechanism of the present invention as attached to a loom;

Fig. 2 is a view in perspective showing the 'preferred form-of the entirelet-off mechanism in detail; V r

Fig. 3 is a perspective View showing the whip roll support and levers connecting to the weight in this form of construction;

Fig. 4 is a side elevation of the whip roll and positive let-off mechanism;

or stretching of the threads, reacts imme- 7 self.

after which the vrotatably fastened to has longitudinal grooves limited by stops 4 hers I to determine downward movement and Fig. 5 is an end view showing the let-off mechanismand whip roll support with its fulcrum in section;

Fig. 6 is a side view partly in section showing the whip roll mounting and the fulcrum of the whip roll arm in both of which anti-friction bear- 7 ings are employed, asindioated;

Fig. 7 is a sectional view of the link connecting the pivoted lever bearing a weight, and the memb'er connecting the ends of the whip roll support arms;

Fig. 8 is a perspective view of the socket in which the whip roll supportarms are pivoted;

Fig. 9 is aperspective view showing the structure of the whip roll support arms at their pivo'tedends;

Fig. 10 is a perspective view of the shaft which forms the pivot;

Figs. 11 and 12 are diagrammatic views showing the path of the threads for varying positions of the whip roll; and

Fig. 13 is a section taken through the line 13-13 of Fig. -5 and shows the gearing which operates the warp beam.

Referring in detail to the drawings, the let-off or loom feederis mounted on frame members .I provided for each end of the let-off. On the outer face of each of these frame members is a T-shaped groove 2 for mounting the frame members upon the loom structure designated as 3 in Fig. 2. Any other suitable sort of mounting may, of course, be employed to fasten the frame members I to the loom supports 3 or the frame members I maybe apart of'the loom frame-it- The frame members I preferably have sockets 20 at their upper ends into which extend whip roll support arms 22. At the end of the whiproll support arms22 are provided openings 23 (Fig. 9) for shafts 24 and 24a. Figs. 8, 9 and 10 taken together represent an exploded view of the pivot construction. Whiproll support arm 22 (Fig. 9) is inserted into the socketj20 (Fig. 8)

shaft 24a (or through the openings 20a in the socket and 23 in the whip roll support arm. The shafts 24 are mounted in'ballbearings 26, (see Fig. 5), which slide into openings Zila provided in the sides of sockets 20. By this arrangement the whip roll support arms 22 are free to move about the pivot defined by the shaft 24 with a minimum amount of friction or resistance.

. The shaft 24 where it passes through whip roll support 22 should make a tight sliding joint. The shaft 24a must be keyed or otherwise nonwhip roll support arm 22w. To secure this non-rotatable relationship a key way 260 (Figs. 5 and 9) is formed in the shaft and opening in whip roll support arm 22a respectively into which a key 26| (Fig. 10) is placed. The shaft 24a, after passing through the roller bearings 26 and whip roll support arm 22a, is enlarged as shown at 262. This enlarged portion 263 (Fig. 10) to form a non-rotatable connection with a goose neck lever 30 the function of which will be described subsequently in connection with the positive let-off control. 7 v

The extent of the movement ofthe arms 22 is provided on the frame memextensions 28 provided on the whip roll support arms 22 which when the whip roll support arms 22 are raised contact with the top of thesockets 20; A whip roll 20!! is mountedon the whip roll support arms 22 by means of mountings 202 pro- 24) is insertedvided on each of the whip roll support arms 22. These mountings 202 are arranged so that the whip roll 200 has an effective position above the pivot of the whip roll support arms 22 and between the pivot and the other end of the arm. The whip roll support arm 22, and whip roll mounting 202 may, if desired, take the form of a bell crank lever.

The whip roll mountings 202 (Fig. 6) are provided with openings 264 into which the whip roll shaft 206 may slide. A recess 208 is provided in the whip roll mounting 262 to contain ball bearings 2 iii. The whip roll 200 is thus free to rotate on the ball bearings 2m and has an effective position on a mid-point of the whip roll support arms 22. The whip roll support arms 22 have a downward obtuse bend about two-thirds of their length from the pivot to place the connections between them below the path of the threads and avoid contacts with them. The non-pivoted end of the whip roll support arms 22 are joined by a member 2 I 2. A practically rigid joint is obtained by nuts 2M threaded to the member 2l2 and tightened against both sides of each whip roll support arm 22. Since the force applied to the member M2 is at the ends and at the center, a truss rod 2i6 is arranged between the ends of the member 2l2. The truss rod M6 is anchored at each end of the member 212 by means of anchors 2l8 provided with nuts and bolts 228 which pass through the member 2l2. The truss rod between the two anchors 2E8 passes over the groove 2E9 in the truss member 22| which is fastened around the shaft as a bifurcated collar to provide room between the bifurcations for a collar 222. The truss member ZZI is held in position by set screws 224.

Pivotally mounted on the member 2l2 between the bifurcated collar of truss member 22! is collar 222 provided with a shouldered projection 226 (Fig. 7) to slidably engage a link or connecting pipe 228. Into the opposite end of the connecting pipe 228 is inserted a threaded plug 230 provided with a shoulder 232 to limit the extent to which the plug 280 can enter the member 228. A threaded rod 234 passes through the threaded plug 230 and is at the other end threaded into bifurcated member 236 and held in position with respect thereto by a lock nut 238, The length of the link between the connecting member 2|2 and a pivoted lever 240 may be adjusted by varying the position of the plug 230 on the threaded rod 234. For normal operation the pivoted lever 240 should be set horizontal when the whip roll support arms 22 are horizontal. The bifurcated member 236 is attached to a pivoted lever 246 by means of a pin 242. The pivoted lever 240 is fulcrumed at 243 by a bifurcated member containing a pin 244 which passing through an opening in the pivoted lever 240 forms a fulcrum therefor.

Pivoted lever 240 is provided for a considerable part of its length with teeth 246 to hold in place a weight 248 which acts through the pivoted lever 240 to control the tension on the threads.

The operation of that part of the invention thus far described is as follows: threads passing over the whip roll 200 exert a downward force on the whip roll which having an effective position at a midpoint on support arms 22 exerts a downward force on the entire arm. Since the arm is pivoted on shaft 24 and the force is applied near the fulcrum there is a strong tendency for binding at this point but by providing an anti-friction mounting of ball or roller bearings this binding action is overcome and forces applied to thewhip roll do not tighten the fulcrum but it is at times free floating and therefore responsive to small changes in the forces applied. The downward forces on the whip roll are communicated by means of the pivot on shafts 24 through the whip roll support arm 2I2 and link 228to the the weight 248. Considered conversely, the force exerted by the Weight 248 acts upon the pivoted lever 240 through the link 228 to pivoted whip roll supporting arms 22 which carry the whip roll 200. For any given: setting of the weight 248 a corresponding force is applied by Whip roll 200 to the threads passing over it to maintain a tension on them and this tension remains constant for any and all positions of the whip roll between the two extremities of its variable positions.

It is thus apparent that any shortening of the threads passing over the whip roll 200 tends to raise the weight 248 and any lengthening of the threads passing over the whip roll 200 lowers the weight 248 and raises the whip roll to maintain pivoted lever 240 holding at all times a constant uniform tension on the A more detailed description of the 0per-,

threads. ation of this device and its effect on the rate of let-off will be given later in connection with the other parts of the machine.

At the end of one of the shafts 24 designated as 2411 .is provided an extension containing longitudinal surface grooves 263 or knurling. vMounted on this extension of the shaft 2466 is a goose neck lever 30. The goose neck lever is non-rotatably mounted on the shaft 24a to-form a bell crank lever with respect to whip roll support arms 22 and the longitudinal grooves thereon assist in preventing any rotation. The opening in the goose neck lever 30 is large enough to permit rotation on the knurled shaft 24a to make necessary adjustments. A slot 32 (Fig. 4) extending to the opening for shaft 24a is provided in the goose neck lever 30 at right angles to which a nut and bolt assembly 34 passes. By means of this nut and bolt assembly 34 the opening in the slot 32 can be decreased and the connection between the goose neck lever 30 and the shaft 24a tightened.

The goose neck lever 30 extends downwardly around the shaft 36 and at its end below the shaft 36 is provided with aflanged bolt 38 which is adapted to slide within a slot 300 provided in an extension of a pawl guard 362 Which is rotatably mounted on the shaft 36. Movements of the goose neck lever vary the position of the pawl guard 302. Also rotatably mounted on the shaft 36 is a pawl lever 304. The pawl lever 304 has pivoted thereon by means of a bolt 306 a pawl 308. The pawl 388 is urged against a ratchet Wheel 3|0 by means of a spring 3l2 which is contained in a recess 344 in the pawl lever 304. The pawl 363 is provided with a relatively sharp point 3l6 to engage the ratchet teeth 3i 8. Near the point of the pawl 3H5, is an opening for axle 320 on which axle is mounted a wheel 322 to rotate on ball bearings 324. The wheel 322 is arranged to ride upon the pawl guard 302 and thereby lift the point 3| 6 out of contact with the ratchet teeth 3H3 when the pawl guard is in certain positions.

The ratchet wheel 3I0 is keyed to the shaft 36 so that rotation imparted to the ratchet wheel 3| 0 will rotate the shaft 36. Also keyed to the shaft 36 is a collar 326 which keeps the pawl lever 364 in position on the shaft against the ratchet wheel 3|0. The collar is fixed to the shaft by all 22, connecting member I washer.334. The ratchet lever 304 is pivotally' connected "with a rod 336 reciprocally operated by a going With the whip roll partiofjtheloom-thus causing a reciprocal motion of the pawl which engages and rotates the ratchet. Connection between the reciprocating rod 336 and the pawl lever 304 issecured by a member 338' which surrounds the rod 336 and is held. in position thereon by nuts 34 and 342. The member 338-is pivoted to the pawl lever 304 by means of a'bolt 344. I 7

Also mounted on the frame members I is a warp beam 40. At one end of'the'warp beam 40 'is provided a worm gear 400. The worm gear 403 is rotated by a worm 462'on a shaft 406 which shaft is rotated by the" shaft 36 through bevel gears 408. The gearing including the beveled gears, worm and worm gears are covered by a housing 42 which is held in place by bolts 44passing through a flange 46 provided on one of the frame members I.

To adjust the let-off the whip roll support arms 22' are-raised to their highest position when the projections '28 contact with the top of socket 20. in this position as shown in Fig. 4 the goose neck lever 30 is fastened to shaft 24a in arpositionwhich permits about one eighth inch clearance betweenzthe neck of the lever and the spacer 3'! which separates the pawl guard 302 and the housing 42 on the shaft 36. This adjustment when once madeis permanent and need not be repeated. To adjust the feed the lay sword 506 is opened to the position shown in dotted lines on Fig. 1.

The goose neck lever is maintained in the position described in the preceding paragraph, that is with a small amount of clearance between it and the spacer 31 on the shaft 36 and with the whip roll support at its upper extremity. The length of the rod 336 between the pawl lever 304 and the lay sword 506 is then adjusted so that the pawl 308 has its point 3; almost to the end of the pawl guard in the manner shown in Fig. 4. Fig. 4 shows the position of the parts to complete the adjustment if the lay sword which is connected to rod 336 is open.

' To operate the let-off in connection with a loom a warp beam containing the warp threads wound thereon is placed in position on the shaft 342: and the warp threads are passed over the whiproll 200 around lease rods 50 and 5| to the harness 52 continuing through the reed 53 and over the lay 54. At this point they have been woven into cloth and the cloth continues over the breast beam 55 around the roller 56 to the draw off roll 51. Rollers 58 and 59 assist in keeping the cloth in contact with the draw ofi roll from which it passes to the wind up roll 500. The draw off roll 51 is rotated by a pick wheel 502 pawl 504 set in motion by a going part of the loom. The lay sword 506 is operated by a going part of the loom such as a crank motion 508' through a connecting rod 501.

When the let-off or loom feeder has been set as above described and the threads arranged'in the manner indicated, the loom and loom feeder should be adjusted for the particular work at hand.

The draw off rollis rotated or the warp beam draw off, etc., will operated by a is turned by means of the-crank until the threads passing over the whip roll will'draw taut and the whip roll'is-depressed until the main partof the whip roll support arm-22 is substantially horizontal as shown in Fig; 1. With the whip roll in this position the weight 248 is adjusted on piv-' oted lever- 240 by moving it'along the teeth 246. If a high tension is desired on the warp threads the'weight 248' is moved" toward the end of the pivoted lever 240 away'from the fulcrum. If a lower tension is desired the weight is moved toward the fulcrum. It should 7 be realized, of course, that the size of the weight and its position on the pivoted lever 240 can be varied within very wide limits according to the tension desired upon the threads. V Figs. 11 and 12 illustrate the operation of the whip roll in maintaining a uniform tension on the threads at all times. started after the adjustments above described the whip ro-ll might be in the position indicated at A in Fig. 11 and the threads between the warp beam 40 and the lease rod 55 will have a length equal to the distance along the path X-Y-Z. Due to the weight 248 operating to keep the whip roll in position against the warp threads, a tension, dependingupon the size and position of the weight, will be imposed upon thethreads. After the loom has operated the shedding, picking, tend to shorten the distance between the warp beam 43 and the lease rod 50 as shown in Fig. 12. This will tend to cause the whip roll .to assume the position B in Fig. 12;

However, the tension on the threads will be exactly what it was at the time the whip roll was in position A due to the weight operating on the whip roll. It will therefore be evident that until the whip roll has been so depressed that the whip roll support arm 22 has contacted with the stop 4 (Fig. 4) the tension on the threads will always remain constant. In operation, however, the

whip roll support arm 22 would not come into contact with the stop 4 because as the whip roll is depressed it operates to increase the rate of let-off. V r

As shown in Fig. 4 when the whip roll support arm 22 has been raised to its upper extremity reciprocal movement of the rod 336 would cause the pawl lever 304 to oscillate, but during these oscillations the pawl 308 would not operate the ratchet 310 because the wheel 322 would ride upon the pawl guard 32.

When the whip roll support arm 22 assumes a horizontal position, as shown in Fig. 1, the goose neck lever 30 is moved causing the pawl guard 302 to move back on the ratchet wheel 3| and permitting the pawl 308 to engage the teeth 318 of ratchet wheel 3"! for a portion of its stroke.

When the warp beam is full the whip roll support arm 22 tends to assume a position slightly above the horizontal and at each stroke of the reciprocating rod 336 only a few teeth are then engaged in the ratchet wheel 3I0.

As the warp beam decreases in diameter, it is necessary for the ratchet 3|0 to rotate more rapidly to allow a constant let-off. If the leton is not sufiiciently rapid the threads between the warp beam and the lease rod 50 tend to short- 7 'en and in so doing depress the whip roll 200 and the whip roll support arm 22. When this occurs the whip roll support arm 22 may be forced to a position below the horizontal and accordingly the goose neck lever 30 moves the pawl guard farther back on the ratchet 3l0 permittingthe When the loom is first pawl 308 to engage more teeth on each the reciprocating rod 336.

In this way the let-ofi from the warp beam is so controlled that regardless of the diameter of warp beam, the amount of thread let oiT is always suflicient to take care of that wound on the draw off roll.

At all times during the operation the whip roll is urged against the threads with a constant force, and, therefore, the tension on the threads is constant throughout the weaving operation regardless of the position of the whip roll between the two extremities of its position.

It will be appreciated that due to shedding, laying and picking, the whip roll support arm 22 may be caused to vibrate rather rapidly within a small distance but the average position during these vibrations determines the rate of let off and at all times the tension of the threads is constant.

Referring to the 1 and 4, it will be length of the whip roll arm to the whip roll support arm 22, or weight arm about the pivot 24a, is approximately one to three, which has been found to give the smoothest and most rapid compensation in operation of the let-01f mechanism.

Referring more particularly to the drawings, it will also be noted that the whip roll support comprises a lever of the second class, preferably a bell crank lever, in which the arms of each lever, comprising the short whip roll mounting arm 202 and the longer whip roll support arm 22 thereof extend during operation of the let-01f mechanism toward the loom each other at a small angle, which in the preferred embodiment of the invention as shown in the drawings is an angle of about 45.

It will be apparent from the drawings, referring particularly to Figs. 1 and 2, that the whip roll is preferably mounted on a bell crank lever which is pivoted in such a position that oscillation or movement of the whip roll is in substantially the median plane between the threads passing to and from the whip. roll, or in other words, the movement of the whip roll about the pivot 24, 24a of the arm is in substantially the plane of the resultant of the forces of tension in the warp threads.

It will be obvious, however, that oscillation or movement of the whip roll is in an arc each point of which, through the small arc of movement, will coincide substantially with a corresponding point on the line representing the resultant of forces in the warp passing over the whip roll as determined substantially by the instantaneous bisector of the angle determined by the plane of the warp threads passing to the Whip roll and the plane of those passing from the whip roll.

It will be obvious that in a given construction the position in which the whip roll and its support should be pivoted may be readily determined graphically, with a whip roll of given diameter, by indicating the positions of the warp thread sections passing to and from the whip roll and bisecting the angle between the warp sections passing to and from the whip roll, which bisector represents the plane of the resultant of the forces of tension in the warp thread sections passing to and from the whip roll. By drawing a line from the center or axis of the whip roll at right angles to this resultant or bisector of the angle, the line so drawn is the locus of points along which the said pivot should be located. The particular point along this line at which the pivot stroke of drawings, particularly Figs.

should be located may be readily determined in view of 'the particular conditions or dimensions of the particular device by anyone skilled in the art.

mechanism this angle remains obtuse, so that in the form of construction shown in the drawwhip roll oscillates about its pivot in accompanying claims.

We claim 1. In a let-01f for a loom, the combination of a positive let-off warp beam, a whip roll support engaged by the pawl.

2. In a let-01f for a loom, the combination of a positive let-off warp beam, a whip roll support comprising pivoted arms extending toward the loom, anti-friction bearings at the pivots, a rigid member connecting the ends of the pivoted arms, mounting having an effective position supporting a weight to maintain a constant tension on the threads passing over the whip roll regardless of shedding or picking, an adjustable link connecting the rigid member between the ends of the pivoted arms and said pivoted lever at a point opposite the weight, and means responsive to the position of the whip roll lever for controlling the rate of rotation of the Warp beam.

3. In a let-off mechanism for a loom, in combination with a warp beam, a pair of Whip roll supporting arms, pivoting the outer ends of said arms, a heavy cross member rigidly connecting the inner ends anti-friction bearing means for 7 10. for balancing the downward force exerted by the cross member. 7

4. In a let-off mechanism for a loom, incombination with a warp beam, a pair of whip roll supporting arms, each pivoted at its outer end in 15 anti friction bearings, the inner ends of the arms being connected by a heavy rigid cross-member for forming with the arms a substantially rigid whip-roll frame, a whip roll rotatably mounted on said arms, and means for applying substan- 20 'tially at the middle of said cross-member a controllable-upward force for balancing the said frame, whereby a single force-applying means controls said frame and applies a uniform tension to the warp. 7 7 25 e 5. In a let-off mechanism for a loom, in combinationv with a warp beam, a pair of whip roll supporting arms, each pivoted at itsouter end in anti-friction bearings, the inner ends ofthe arms being connected by a heavy rigid cross 30 member for forming with the arms a substantially rigid whip roll frame, a whip roll rotatably mounted onsaid arms, andmeans comprising a weight-controlled lever having an adjustable weight thereon for applying substantially at the 35' middle of saidcross-member an upward force for balancing the said frame, said weight controlled lever being a lever of the first class, having its fulcrum supported at the base of the machine, whereby a single adjustable weight means on the 40 power arm of said lever controls the whip roll frame.

6. In a let-off mechanism for a loom, in combination with the warp beam and its support, a whip roll supporting frame comprising a pair of 4 arms, the outer end of each arm being rigid with two stub shafts respectively, anti-friction bearings on which said stubshafts are journaled, a ratchet controlling arm for the warp beam ratchet. rigidly secured on one of said stub shafts,

50 a heavy cross-member secured to the inner ends of the said arms for completing a substantially rigid whip-roll frame, and bearing means for the whip-roll on said arms.

'7. In a let-off mechanism for a loom, in combination with the warp beam and its support, a

55 whip-roll supporting frame comprising a pair of arms, the outer end of each arm being rigid with two stub shafts respectively, anti-friction bearings on which said stub shafts are journaled, a ratchet controlling arm for the warp beam ratchet rigidly secured on one of said stub shafts, a heavy cross member secured to the inner ends of the said arms for completing a substantially rigid whip-roll frame, anti-friction bearing means for the whip roll on said arms and means comprising a weighted lever of the first class operatively connected to the middle of said crossmember, whereby a single adjustable weight means is used for balancing the whip-roll frame.

8. A let-off mechanism for a loom comprising incombination a warp beam, a whip roll support including supporting arms pivoted above the warp beam and extending toward the loom from their pivots,"a whip roll supported by said arms be- '15 tween the pivots and the inner ends of the supanaoec porting arms thereby forming levers of the second class, the said whip roll being sopositioned with respect to the said pivots and to the warp beam that the threads passing from the warp beam during operation pass over the whip roll forming an obtuse angle so that the whip roll oscillates normally in a small are substantially coinciding with the plane of the resultant of the tensions in the warp threads or in other words substantially in a" plane midway between the warp threads passing to and from the whip roll, anti-friction bearings for the pivoted ends of said arms, means rigidly connecting'the inner ends of the supporting arms and forming therewith a rigid frame means engageable with said frame to counterbalance it and maintain a uniform tension on the threads passing over the whip roll, means operated by a going part of the loom for positively rotating the warp beam and means responsive to the position of the whip, roll for controlling the'rate of rotation.

9. A let-ofi mechanism for a loom comprising a Warp beam, a whip roll, lever means for mount ing said whip roll for movement about a stationary pivot so that during operation of. said mechanism the whip roll may oscillate in a plane passing through the axis of the whip roll' and substantially midway between the warp threads passing to and from the whip roll, whereby counterbalancing forces operate to maintain or shift the position of the whip roll in substantially said plane with a turning moment about said stationary pivot, anti-friction bearings at the said stationary pivot serving to float the said whip roll without appreciable friction, means connected to said lever means operating to shift the position of the whip roll in response to changes in the length of warp threads passing from the whip roll, means for rotating the said Warp beam and means operatively connected to the whip roll to, control the rate of let-off from said warp 10. A let-off mechanism for a loom comprising a warp beam, a whip roll, lever means of the second class for mounting said whip roll for movement about a. stationary pivot, said lever having a whip'roll arm substantially one third of the other arm, and so positioned that the whip roll may oscillate in substantially the plane passing midway between the angle formed by the warp threads passing to and from the whip roll, force pp y to maintain the whip roll in contact with the warp threads to produce a predetermined tension in the said threads, anti-friction bearings at the saidstationary pivot serving to float the said whip roll without appreciable friction, means for rotating the said warp beam and means means connected to said other arm.

operatively connected to the whip roll to control the rate of leteoff from said warp beam in accordance with oscillating movements of the whip roll.

II. In a let-off mechanism for a loom, the

combination of a warp beam, a whip roll mounting comprising a lever pivoted at its fulcrum in anti-friction bearings, a whip roll mounted on said lever in anti-friction bearings in a position so that during operation of the mechanism the thread sections passing from the warp beam to the whip roll, and those passing from thence to 'the loom make and maintain an obtuse angle at the whip roll whereby the resultant of the forces of tension in the thread sections operates directly on the whip roll in a direction to cause a turning moment about the fulcrum without substantial friction losses due to force or a component thereof acting on the pivot, means to urge the whip roll against the warp threads with a substantially constant force, means for rotating the warp beam and means responsive to the position of the whip roll for controlling the rate of let-off from the warp beam.

12. In a let-oiT mechanism for a loom, the combination of a warp beam, a pivoted whip roll support having arms extending in the direction of the loom, anti-friction bearings at the pivot of said support, a whip roll mounted on one of said arms of said whip roll support, force-applying means operating on the other of said arms so as to move the whip roll into successive posi tions to maintain uniform tension on the threads passing over the whip roll regardless of variations due to shedding or picking, said whip roll being mounted on the whip roll support in a position intermediate between said pivot and said operating means so as to maintain an angle substantially greater than a right angle between the threads passing to and from the whip roll, said pivot being positioned with respect to said whip roll during the operation of the mechanism so as to cause oscillation of the whip roll in substantially the median plane between the said threads, or in other words in an arc substantially tangent to the median of said angle, means for rotating the said warp beam to permit letofi of the warp threads and means operating with changes in the position of the whip roll for controlling the rotation of the warp beam.

13. In a let-off mechanism for a loom, the combination of a warp beam, a whip roll, a pivoted whip roll support, anti-friction bearings at the pivot of said support, said support including a bell crank lever having a relatively short whip roll arm and a longer control arm, the bell crank lever being mounted with the arms extending in a direction toward the loom during operation, with the whip roll arm diverging upwardly from the other arm at a relatively small angle, the length of the whip roll arm being substantially one third that of the other arm, force applying means connected to said other arm to maintain constant tension on the threads passing over the whip roll, the said whip roll being so mounted with respect to said pivot and to the warp beam that movement of the whip roll is in substantially the median plane between the threads passing to and from the whip roll thereby substantially eliminating friction losses due to thrust or pull on the said pivot, means for rotating the said warp beam, and means operating with changes in the position of the whip roll to control the rate of let-off from said warp beam.

14. In a let-off mechanism for a loom, the combination of a warp beam, a whip roll, a pivoted whip roll support, anti-friction bearings at the pivot of said support, the said whip roll being mounted on said whip roll support by means of a bell crank lever the arms of which are in a one to three ratio and diverge from each other at an angle of about 45, the length of the whip roll arm being substantially one third that of the other arm, force applying means connected to said other arm to maintain constant tension on the threads passing over the whip roll, the said whip roll being so mounted with respect to said pivot and to the warp beam that movement of the whip roll is in substantially the median plane between the threads passing to and from the Whip roll whereby movement about its pivot is in substantially the plane of the resultant of the forces of tension in the warp threads thereby substantially eliminating friction losses due to thrust or pull on the said pivot, means for rotating the said warp beam, and means operating with changes in the position of the whip roll to control the rate of let-01f from said warp beam.

15. A let-ofi mechanism for a loom, comprising a warp beam, a whip roll, lever means of the second class for mounting said whip roll from a stationary pivot or fulcrum, the said whip roll being so positioned with respect to its pivot that in its normal position during operation a line drawn from the axis of the whip roll at right angles to the resultant of the forces of tension in the warp threads passing over the whip roll would pass through said pivot, anti-friction bearings at the said stationary pivot, means operating on said lever to shift the position of the whip roll to maintain the tension on the warp threads constant during operation of the mechanism, means for rotating the said warp beam and means operated by oscillating movement of the whip roll to control the let-oil from the warp beam.

16. A let-01f mechanism for a loom comprising a warp beam, a whip roll, lever means for mounting said whip roll for movement about a stationary pivot including a whip roll arm and a supporting arm, said arms having respective lengths of substantially a one to three ratio, said lever means being mounted so that during operation of said mechanism the said whip roll may oscillate substantially midway between the portions of the warp threads passing to and from the whip roll, anti-friction bearings at the said stationary pivot, means connected to said ating to shift the position of the whip roll in response to changes in the length of the Warp threads passing over the whip roll, means for rotating the said warp beam and means operatively connected to the whip roll to control the rate of let-oil from the said warp beam.

17. A let-off mechanism for a loom comprising a warp beam, a whip roll, a pivoted whip roll support comprising a bell crank lever having a relatively short whip roll arm, and a relatively during operation of the let-off mechanism with constant tension on the Warp threads passing over the whip roll, the position of the whip roll with respect to its pivot during operation being such that the whip roll movement is in substanmedian plane between the sections of threads passing to and those passing whip roll, means for rotating the warp beam, and means operating with changes in the position of the whip roll to control the rate of let-off from said warp beam.

18. A let-off mechanism for a loom comprising a warp beam, a whip roll, means for mounting said whip roll for oscillating movement about a stationary pivot, anti-friction bearings at said stationary pivot, the said stationary pivot being so positioned in the said mechanism with respect to the warp beam and the warp threads passing to and from the whip roll that the arc of oscillation of the whip roll is substantially tangent to the median plane between the warp threads passing to and from the whip roll, force applying means operating to shift the position of the whip roll to maintain substantially constant tension on 7 bination pensate 8 the-warp threads during operation of the mechanism, means for rotating the warp beamand means operating with the whip roll to control the rate of let-off from said warp beam.

19. Ina let-off mechanism for a loom, the comof a warp beam, a whip roll, means for mounting the said whip .roll comprising a bell crank lever the arms of which extend at an angle of about 45 to each other, the length of the whip roll arm being substantially. one third that of the weight arm, the said whip roll being mounted in a position so that movement of the whip roll about its pivot is in substantially the plane of to and from the whip roll, anti-friction bearings at the said stationary pivot, means operating to shift the position of the whip roll in response to changes in the length of the Warp threads to maintain substantially constant tension, means for rotating the warp beam and means operating with changes controlling the rate of rotation of the warp beam.

21. A let-ofi mechanism for a loom comprising a Warp beam, a whip roll, a draw off roll, lever i means for mounting said whip roll for oscillation from a stationary pivot in substantially the plane of the resultant of the tensions in the warp passing to and from the whip roll, means operating to shift the position of the whip roll to comfor changes in the length of the warp threads passing to the draw off' roll, means for rotating the warp beam and means responsive to the position of the whip roll for controlling the 7 rate of rotation of the warp beam.

22. In a let-off mechanism for a loom the subcombination comprising a warp' beam, means for changes in the position of r the warp threads passing in the position of the Whip roll for mounting the warp beam for rotation in fixed position, a whiproll, and means for mounting the said whip roll for limited oscillation in pressure engagement with the threads passing from the warp beam over the whip roll to the loom so that the axis of the whip roll will move in substantially the plane of the bisector of the angle between the threads passing to and from the whip roll.

23. A let-off mechanism for a loom comprising a warp beam, awhip roll, anti-friction bearings for said whip roll, lever means of the second class for mounting said whip rollfrom a stationary pivot or fulcrum, anti-friction bearings at the said stationary pivot, force-applying means operating to maintain the position of the whip roll in substantially the plane of the resultants of the tension on the warp threads passing to and from the whip roll, movement thereof being in a direction to maintain substantially constant tension on the warp threads during operation of said mechanism, said force-applying means including a lever ,member mounted on a stationary fulcrum and operatively connected to said lever means to maintain the said whip roll in horizontal position during said operation, means for rotating the warp beam and means operated by movements of the whip roll to control the let-off from said warp beam.

24. In a let-off mechanismfor a loom the subcombination comprising a warp beam, means for mounting the warp beam for rotation in a fixed position, a whip roll, means for mounting the said whip roll for limited oscillation in pressure engagement with the threads passing from the warp beam over the whip roll to the loom so that the axis of the whip roll will operate within a limited space in a wide are substantially tangent to the bisector of the angle between the threads passing to the whip roll and those passing therefrom and anti-friction bearing meansv for facilitating movements of the said whip roll in both its oscillating and turning movements.

EMIL G. JEGGE. GEORGE W. KRETZSCHMAR. 

